domain_conf: Common routine to handle network storage host xml def
domain_conf: Common routine to handle network storage host xml def

In preparation for hostdev support for iSCSI and a virStorageNetHostDefPtr,
split out the network disk storage parsing of the 'host' element into a
separate routine.

rlaager/libvirt,shugaoye/libvirt,olafhering/libvirt,nertpinx/libvirt,jardasgit/libvirt,crobinso/libvirt,datto/libvirt,jardasgit/libvirt,andreabolognani/libvirt,libvirt/libvirt,rlaager/libvirt,olafhering/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,zippy2/libvirt,olafhering/libvirt,taget/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,taget/libvirt,jardasgit/libvirt,rlaager/libvirt,nertpinx/libvirt,zippy2/libvirt,agx/libvirt,VenkatDatta/libvirt,taget/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,elmarco/libvirt,zippy2/libvirt,rlaager/libvirt,jfehlig/libvirt,crobinso/libvirt,olafhering/libvirt,andreabolognani/libvirt,libvirt/libvirt,eskultety/libvirt,crobinso/libvirt,shugaoye/libvirt,datto/libvirt,nertpinx/libvirt,andreabolognani/libvirt,eskultety/libvirt,andreabolognani/libvirt,eskultety/libvirt,zippy2/libvirt,taget/libvirt,eskultety/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,elmarco/libvirt,taget/libvirt,elmarco/libvirt,rlaager/libvirt,datto/libvirt,eskultety/libvirt,shugaoye/libvirt,libvirt/libvirt,agx/libvirt,agx/libvirt,agx/libvirt,andreabolognani/libvirt,datto/libvirt,shugaoye/libvirt,crobinso/libvirt,agx/libvirt,nertpinx/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,elmarco/libvirt,libvirt/libvirt,jardasgit/libvirt,elmarco/libvirt,shugaoye/libvirt,datto/libvirt